1. Technical Field
The present invention relates to a synthetic resin thin-walled bottle container comprising a mouth portion for filling or discharging contents, a body portion extending from the mouth portion, and a heel portion provided at a bottom part of the body portion, for placing the body portion thereon in a self-supporting manner.
2. Related Art
Synthetic resin thin-walled bottle containers are thinner than ordinary bottle containers and are thus capable of achieving light-weighted containers and reduction in the volume of wastes. As such, this sort of synthetic resin containers are used as refill containers for detergents for kitchen use, bathroom use and the like.
Meanwhile, the thin-walled bottle containers are sometimes used as they stand, and are thus provided with an annular heel portion near a bottom surface of the container's body portion so as to cause the container itself to self-support on a supporting surface such as shelf or table. Further, the heel portion comprises a sidewall having a curved surface bulged toward the outside of the container relative to said sidewall, a flat and annular bottom face region continuous to the sidewall, and a bottom-up region continuous to the bottom face region and inwardly recessed toward the vicinity of a bottle's center axis.
This sort of thin-walled bottle containers are stretch blow molded from a thermoplastic synthetic resin such as polypropylene (PP), so that the molded article (bottle container) has a non-uniform wall thickness, thereby failing to completely eliminate occurrence of so-called “thickness deviation”. Therefore, when it is contemplated to further reduce the resin amount in a conventional thin-walled bottle container in view of environmental problems, the bottle container in a contents-filled state may cause inclination and/or buckling at a thin-walled region of the heel portion where the thickness-deviation has occurred, under a load applied in a center axis direction of the container.